Establishment and Optimization of ISSR-PCR Reaction System for Cymbidium ensifolium (Linn.) Sw

[Objective] This research aimed to search a best method for extracting the genomic DNA of Cymbidium ensifolium and establish the optimized ISSR-PCR reaction system.[Method] Genomic DNA was extracted from C.ensifolium leaves by modified CTAB method.ISSR-PCR reaction system for C.ensifolium was optimized.[Result] High-quality genomic DNA was obtained from C.ensifolium.The 25 μl optimized ISSR-PCR reaction system for C.ensifolium contained 2.5 μl 10× PCR buffer,2.5 mmol/L MgCl2,240 ng template DNA,160 μmol/L dNTPs,1.25 U Taq DNA polymerase,0.4 μmol/L primer and 15.78 μl ddH2O.The optimal PCR procedures were：94 ℃ pre-denaturation for 5 min and then 40 cycles,94 ℃ denaturation for 30 s,50-60 ℃ annealing for 30 s （annealing temperature according to different primers）,72 ℃ extension for 50 s and a 72 ℃ extension for 7 min.[Conclusion] An optimized ISSR-PCR reaction system for C.ensifolium was established,which provides a basis for further study on genetic diversity of C.ensifolium by using ISSR molecular marker technique.

Optimization of ISSR-PCR Reaction System and Preliminary Construction of ISSR Fingerprinting of Some Species in Bryaceae

[Objective] The aim was to provide molecular basis for the identification of species in the moss family Bryaceae by the construction of inter-simple sequence repeats （ISSR） fingerprinting. [Method] In order to seek standardizing PCR reaction set-up, an orthogonal design was used to optimize ISSR-PCR amplification system of Bryaceae in five factors （Mg2＋, dNTPs, primer, DNA template, Taq DNA polymerase） at four levels respectively. [Result] A suitable ISSR reaction system was obtained, namely： 20 μl reaction system containing 5 ng of DNA template, 0.2 μmol/L primer, 2.25 mmol/L MgCl2, 0.6 U of Taq DNA polymerase, 0.4 mmol/L dNTPs. Proper annealing temperature was found at 48-50 ℃.The above system and six ISSR-PCR primers were used for the PCR amplification of 14 samples from Bryaceae and the related species in Mniaceae. A total of 86 bands were amplified, all showed polymorphism. NJ cluster analysis showed a star-shaped cladogram. [Conclusion] The results manifested that ISSR fingerprinting could provide the appropriate degree of polymorphism at low taxonomic level, so it would be a useful tool to provide additional evidence for resolving taxonomic relationships at the species level of Bryaceae.

Optimization of SSR-PCR Reaction System and Screening of Polymorphic Primers for RIL Parents

[Objective] This study aimed to establish a high-efficiency and stable SSR amplification system and screen polymorphic primers in order to further compare the tri-group probability analysis method and traditional QTL mapping method. [Method] In this study, we preliminarily screened the 605 pairs of primers evenly distributed on the 12 chromosomes through investigating their polymorphism performance in amplification, and established an optimized SSR-PCR reaction system. [Result] A 10μL SSR-PCR reaction system suitable for rice was set up as fol ows： 2 μl of 10 × Buffer, 2.0 mmol/L Mg2＋ （final concentration）, 0.5 mmol/L dNTPs, 1.0 μmol/L primers （final concentration）, 1 μl of DNA template, 0.15 U Taq DNA polymerase. Among the SSR primers distributed over the genome, 142 pairs that were polymorphic upon the parents were screened. [Conclusion] This study lays a good foundation for sub-sequent QTL mapping studies.

Establishment and Optimization of ISSR-PCR Reaction System for Cymbidium faberi Rolfe

[Objective] By using the genomic DNA of Cymbidium faberi Rolfe as template,the factors that affect the result of ISSR-PCR reaction system were researched and the optimal system was established.[Method] The genomic DNA was extracted from C.faberi Rolfe with method of modified CTAB.Different factors which affected ISSR amplification reaction were optimized.[Result] High-quality genomic DNA was obtained from C.faberi Rolfe.And the optimal reaction system was as follows：25 μl amplification reactions system contained 2.5 μl 10 × PCR buffer,2.0 mmol/L MgCl2,60 ng template DNA,160 μmol/L dNTPs,1.25 U Taq DNA polymerase,0.4 μmol/L ISSR primer and 15.85 μl ddH2O.The optimal amplification procedures were pre-denaturing for 5 min at 94 ℃,followed by 40 cycles of denaturing for 30 s at 94 ℃,annealing for 30 s at a temperature of 2-3 ℃ lower than melting temperature of each primer pair,extension for 50 s at 72 ℃.Then extension step of 7 min at 72 ℃ was performed.[Conclusion] The optimal system could provide a favorable basis for further study on genetic diversity of C.faberi Rolfe by using ISSR molecular marker technique.

木本油料植物无患子SSR特征分析及SSR-PCR反应体系构建

无患子(Sapindus saponaria L.)是集生物柴油、药用、生态等多种用途于一体的经济型木本油料。本研究利用MISA软件挖掘了无患子叶片转录组中的SSR,对搜索到的SSR进行了特征分析,构建并优化了无患子SSR-PCR反应体系。结果表明,无患子叶片转录组共有Unigene条数目为52460条,其中含有SSR的Unigene有7014条,共检索到8654个SSR。经统计,SSR丰富度从二至六核苷酸依次减少,依次有4327、2669、634、208、161个。SSR长度范围在12~250 bp之间,长度小于等于15 bp的有3619个,均为二和三核苷酸;长度大于15 bp的有5035个,以二、三核苷酸居多。所有SSR共有435种不同重复单元。SSR不同类型重复基元频次分布在4~30次之间,主要分布在4~10频次,共有7090个SSR位点,占总频次的89.65%。SSR位点靶基因GO功能注释显示,无患子叶片转录组Unigene可分为3大类别51个小组;KEGG功能注释显示5大类别中,代谢通路占比最高为65.18%。通过对无患子SSR-PCR反应体系构建与优化,无患子SSR-PCR反应体系最佳组合为:循环次数37次、退火温度60℃、引物量2.0μL、DNA模板浓度为40 ng/μL。

Reaction视频中用户弹幕信息交互行为的情感反应生成机理研究

深入挖掘Reaction视频中弹幕信息交互行为的情感反应机理有助于理解用户弹幕创作背后的情感生成原因及情感变化过程。本文基于情感反应模型,利用定向内容分析法对哔哩哔哩网站中11个热门视频的弹幕信息资源、视频内容以及reactor反应情况展开编码研究,构建了Reaction视频中用户弹幕信息交互行为的情感反应生成机理模型。研究发现,Reaction视频弹幕信息交互行为中的情感反应生成机理总体上遵循“信息刺激-情感反应”的路径,信息刺激有时会独立唤醒情绪或特定情感态度,有时也会通过唤醒特定情感态度进而影响情绪或内化情感态度的生成。该模型有助于提升情感反应理论在计算机协助交流中的情境化探索,也将为社交媒体中用户与信息交互提供优化建议。

Tuning electronic structure of RuO_(2)by single atom Zn and oxygen vacancies to boost oxygen evolution reaction in acidic medium

The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct activity-stability trade-off model is full of significance but challenging.Herein,a single atom Zn stabilized RuO_(2)with enriched oxygen vacancies(SA Zn-RuO_(2))is developed as a promising alternative to iridium oxide for acidic oxygen evolution reaction(OER).Compared with commercial RuO_(2),the enhanced Ru–O bond strength of SA Zn-RuO_(2)by forming Zn-O-Ru local structure motif is favorable to stabilize surface Ru,while the electrons transferred from Zn single atoms to adjacent Ru atoms protects the Ru active sites from overoxidation.Simultaneously,the optimized surrounding electronic structure of Ru sites in SA ZnRuO_(2)decreases the adsorption energies of OER intermediates to reduce the reaction barrier.As a result,the representative SA Zn-RuO_(2)exhibits a low overpotential of 210 mV to achieve 10 mA cm^(-2)and a greatly enhanced durability than commercial RuO_(2).This work provides a promising dual-engineering strategy by coupling single atom doping and vacancy for the tradeoff of high activity and catalytic stability toward acidic OER.

Exciting lattice oxygen of nickel–iron bi-metal alkoxide for efficient electrochemical oxygen evolution reaction

High efficiency,cost-effective and durable electrocatalysts are of pivotal importance in energy conversion and storage systems.The electro-oxidation of water to oxygen plays a crucial role in such energy conversion technologies.Herein,we report a robust method for the synthesis of a bimetallic alkoxide for efficient oxygen evolution reaction(OER)for alkaline electrolysis,which yields current density of 10 mA cm^(-2)at an overpotential of 215 mV in 0.1 M KOH electrolyte.The catalyst demonstrates an excellent durability for more than 540 h operation with negligible degradation in activity.Raman spectra revealed that the catalyst underwent structure reconstruction during OER,evolving into oxyhydroxide,which was the active site proceeding OER in alkaline electrolyte.In-situ synchrotron X-ray absorption experiment combined with density functional theory calculation suggests a lattice oxygen involved electrocatalytic reaction mechanism for the in-situ generated nickel–iron bimetal-oxyhydroxide catalyst.This mechanism together with the synergy between nickel and iron are responsible for the enhanced catalytic activity and durability.These findings provide promising strategies for the rational design of nonnoble metal OER catalysts.

薄壳山核桃SSR-PCR体系优化及引物筛选

【目的】为建立薄壳山核桃SSR-PCR的最佳反应体系,筛选薄壳山核桃高多态性SSR引物,为薄壳山核桃构建指纹图谱、亲缘关系分析、品种鉴定等后续的相关研究提供有力工具。【方法】采用单因素试验与L_(16)(4^(5))正交试验设计相结合的方法,以薄壳山核桃DNA作为模板,对影响薄壳山核桃SSR-PCR反应体系中的6个影响因素(DNA、Mg^(2+)、10×PCR Buffer、引物、Taq酶、dNTPs)进行单因素试验,根据单因素试验的结果确定各影响因素的适宜用量范围,再据此设计正交试验。【结果】根据正交试验扩增结果,确立薄壳山核桃的最佳反应体系(10μL)为:Taq酶0.15 U,Mg^(2+)2.0 mmol/L,dNTPs 0.1 mmol/L,引物1.0μmol/L,50 ng模板DNA 1.0μL,10×PCR Buffer 1.0μL,ddH_(2)O5.8μL。5个因素影响薄壳山核桃SSR-PCR反应体系的扩增效果,其影响程度大小依次为Taq酶>引物=DNA>Mg^(2+)>dNTPs。以8种薄壳山核桃DNA为模板,4对薄壳山核桃引物对优化后的薄壳山核桃SSR-PCR反应体系进行验证,均扩增出明亮清晰的条带,证明优化后的反应体系稳定可靠。利用优化后的反应体系在283对核桃及山核桃引物中筛选出高多态性薄壳山核桃引物12对,其多态性位点信息数均高于0.5。【结论】优化后的反应体系及筛选出的12对薄壳山核桃引物可直接用于后续的SSR分子标记试验,为薄壳山核桃亲缘关系鉴定、交配系统分析等研究奠定理论基础。

Deformable Catalytic Material Derived from Mechanical Flexibility for Hydrogen Evolution Reaction

Deformable catalytic material with excellent flexible structure is a new type of catalyst that has been applied in various chemical reactions,especially electrocatalytic hydrogen evolution reaction(HER).In recent years,deformable catalysts for HER have made great progress and would become a research hotspot.The catalytic activities of deformable catalysts could be adjustable by the strain engineering and surface reconfiguration.The surface curvature of flexible catalytic materials is closely related to the electrocatalytic HER properties.Here,firstly,we systematically summarized self-adaptive catalytic performance of deformable catalysts and various micro–nanostructures evolution in catalytic HER process.Secondly,a series of strategies to design highly active catalysts based on the mechanical flexibility of lowdimensional nanomaterials were summarized.Last but not least,we presented the challenges and prospects of the study of flexible and deformable micro–nanostructures of electrocatalysts,which would further deepen the understanding of catalytic mechanisms of deformable HER catalyst.

芦笋SSR-PCR反应体系的优化及验证

以芦笋幼叶为材料,采用单因素与L1(643)正交试验相结合的方法,对影响芦笋SSR-PCR反应的3个因素(2×Taq Master Mix,模板DNA,引物)进行优化,并以此为基础通过退火温度和循环次数试验筛选引物最佳退火温度和循环次数。结果表明,芦笋基因组DNA的SSR-PCR最优反应体系为:10μL反应体系中,50 ng·μL^(-1) DNA模板0.125μL,10μmol·L^(-1)上下游引物各0.5μL,2×Taq PCR Mix 3μL,灭菌ddH2O 5.875μL。PCR扩增程序为:94℃预变性4 min;94℃变性30 s,60℃退火30 s,72℃延伸35 s,循环25次;72℃延伸10 min,4℃保存。经5对引物组合和5个不同芦笋品种DNA扩增验证,该体系稳定可靠,可用于芦笋遗传多样性分析、种子纯度鉴定、分子标记辅助育种及重要农艺性状的图位克隆等工作。

Precisely Control Relationship between Sulfur Vacancy and H Absorption for Boosting Hydrogen Evolution Reaction

Ef fective and robust catalyst is the core of water splitting to produce hydrogen.Here, we report an anionic etching method to tailor the sulfur vacancy(VS) of NiS_(2) to further enhance the electrocatalytic performance for hydrogen evolution reaction(HER). With the VS concentration change from 2.4% to 8.5%, the H* adsorption strength on S sites changed and NiS_(2)-VS 5.9% shows the most optimized H* adsorption for HER with an ultralow onset potential(68 m V) and has long-term stability for 100 h in 1 M KOH media. In situ attenuated-total-reflection Fourier transform infrared spectroscopy(ATR-FTIRS) measurements are usually used to monitor the adsorption of intermediates. The S-H* peak of the Ni S_(2)-VS 5.9% appears at a very low voltage, which is favorable for the HER in alkaline media. Density functional theory calculations also demonstrate the Ni S_(2)-VS 5.9% has the optimal |ΔG^(H*)| of 0.17 e V. This work offers a simple and promising pathway to enhance catalytic activity via precise vacancies strategy.

Particle agglomeration and inhibition method in the fluidized pyrolysis reaction of waste resin

This work investigated the pyrolysis reaction of waste resin in a fluidized bed reactor.It was found that the pyrolysis-generated ash would adhere to the surface of ceramic particles,causing particle agglomeration and defluidization.Adding kaolin could effectively inhibit the particle agglomeration during the fluidized pyrolysis reaction through physical isolation and chemical reaction.On the one hand,kaolin could form a coating layer on the surface of ceramic particles to prevent the adhesion of organic ash generated by the pyrolysis of resin.On the other hand,when a sufficient amount of kaolin(-0.2%(mass))was added,the activated kaolin could fully contact with the Na+ ions generated by the pyrolysis of resin and react to form a high-melting aluminosilicate mineral(nepheline),which could reduce the formation of low-melting-point sodium sulfate and thereby avoid the agglomeration of ceramic particles.

Interfacial reaction between AZ91D magnesium alloy melt and mild steel under high temperature

The metallurgical quality control of magnesium(Mg)and Mg alloys in melting process is required to ensure a satisfied mechanical and corrosion performance,while the typical used steel crucible introduces impurities and interfacial interaction during melting process.Therefore,a systematic study about impurities diffusion and interfacial interaction between molten Mg and steel is necessary.In the present study,the interfacial reaction between molten AZ91D Mg alloy and mild steel during melting process was investigated with the melting temperatures of 700℃,750℃ and 800℃.The results show that Al(Fe,Mn)intermetallic layer is the intermetallic primarily formed at the interfaces of AZ91D melt and mild steel.Meanwhile,Al_(8)(Mn,Fe)5is indexed between Al(Fe,Mn)and AZ91D.AlFe_(3)C appears between the mild steel and Al(Fe,Mn)at 700℃ and 750℃,but absent at 800℃ due to the increased solubility of carbon in Mg matrix.It is found that the growth of the intermetallic layer is controlled by diffusion mechanism,and Al and Mn are the dominant diffusing species in the whole interfacial reaction process.By measuring the thickness of different layers,the growth constant was calculated.It increases from 1.89(±0.03)×10^(-12)m^(2)·s^(-1)at 700℃ to 3.05(±0.05)×10^(-12)m^(2)·s^(-1)at 750℃,and 5.18(±0.05)×10^(-12)m^(2)·s^(-1)at 800℃.Meanwhile,the content of Fe is linearly increased in AZ91D with the increase of holding time at 700℃ and 750℃,while it shows a significantly increment after holding for 8 h at 800℃,indicating holding temperature is more crucial to determine the Fe content of AZ91D than holding time.

“Buckets effect”in the kinetics of electrocatalytic reactions

In this study,we systematically investigated the effect of proton concentration on the kinetics of the oxygen reduction reaction(ORR)on Pt(111)in acidic solutions.Experimental results demonstrate a rectangular hyperbolic relationship,i.e.,the ORR current excluding the effect of other variables increases with proton concentration and then tends to a constant value.We consider that this is caused by the limitation of ORR kinetics by the trace oxygen concentration in the solution,which determines the upper limit of ORR kinetics.A model of effective concentration is further proposed for rectangular hyperbolic relationships:when the reactant concentration is high enough to reach a critical saturation concentration,the effective reactant concentration will become a constant value.This could be due to the limited concentration of a certain reactant for reactions involving more than one reactant or the limited number of active sites available on the catalyst.Our study provides new insights into the kinetics of electrocatalytic reactions,and it is important for the proper evaluation of catalyst activity and the study of structureperformance relationships.

Possibilities for the synthesis of superheavy element Z=121 in fusion reactions

Based on the dinuclear system model,the calculated evaporation residue cross sections matched well with the current experimental results.The synthesis of superheavy elements Z=121 was systematically studied through combinations of stable projectiles with Z=21-30 and targets with half-lives exceeding 50 d.The influence of mass asymmetry and isotopic dependence on the projectile and target nuclei was investigated in detail.The reactions^(254)Es(^(46)Ti,3n)^(297)121 and^(252)Es(^(46)Ti,3n)^(295)121 were found to be experimentally feasible for synthesizing superheavy element Z=121,with maximal evaporation residue cross sections of 6.619 and 4.123 fb at 219.9 and 223.9 MeV,respectively.

Effects of Maillard reaction and its product AGEs on aging and age-related diseases

Maillard reaction(MR)is a non-enzymatic browning reaction commonly seen in food processing,which occurs between reducing sugars and compounds with amino groups.Despite certain advantages based on Maillard reaction products(MRPs)found in some food for health and storage application have appeared,however,the MR occurring in human physiological environment can produce advanced glycation end products(AGEs)by non-enzymatic modification of macromolecules such as proteins,lipids and nucleic acid,which could change the structure and functional activity of the molecules themselves.In this review,we take AGEs as our main object,on the one hand,discuss physiologic aging,that is,age-dependent covalent cross-linking and modification of proteins such as collagen that occur in eyes and skin containing connective tissue.On the other hand,pathological aging associated with autoimmune and inflammatory diseases,neurodegenerative diseases,diabetes and diabetic nephropathy,cardiovascular diseases and bone degenerative diseases have been mainly proposed.Based on the series of adverse effects of accelerated aging and disease pathologies caused by MRPs,the possible harm caused by some MR can be slowed down or inhibited by artificial drug intervention,dietary pattern and lifestyle control.It also stimulates people's curiosity to continue to explore the potential link between the MR and human aging and health,which should be paid more attention to for the development of life sciences.

The reaction mechanism and interfacial crystallization of Al nanoparticle-embedded Ni under shock loading

The shock-induced reaction mechanism and characteristics of Ni/Al system,considering an Al nanoparticle-embedded Ni single crystal,are investigated through molecular dynamics simulation.For the shock melting of Al nanoparticle,interfacial crystallization and dissolution are the main characteristics.The reaction degree of Al particle first increases linearly and then logarithmically with time driven by rapid mechanical mixing and following dissolution.The reaction rate increases with the decrease of particle diameter,however,the reaction is seriously hindered by interfacial crystallization when the diameter is lower than 9 nm in our simulations.Meanwhile,we found a negative exponential growth in the fraction of crystallized Al atoms,and the crystallinity of B2-NiAl(up to 20%)is positively correlated with the specific surface area of Al particle.This can be attributed to the formation mechanism of B2-NiAl by structural evolution of finite mixing layer near the collapsed interface.For shock melting of both Al particle and Ni matrix,the liquid-liquid phase inter-diffusion is the main reaction mechanism that can be enhanced by the formation of internal jet.In addition,the enhanced diffusion is manifested in the logarithmic growth law of mean square displacement,which results in an almost constant reaction rate similar to the mechanical mixing process.

Metal-organic-framework-derived copper-based catalyst for multicomponent C-S coupling reaction

Copper-based metal-organic frameworks(Cu-MOFs)are a promising multiphase catalyst for catalyzing C-S coupling reactions by virtue of their diverse structures and functions.However,the unpleasant odor and instability of the organosulfur,as well as the mass-transfer resistance that exists in multiphase catalysis,have often limited the catalytic application of Cu-MOFs in C-S coupling reactions.In this paper,a Cu-MOFs catalyst modified by cetyltrimethylammonium bromide(CTAB)was designed to enhance mass transfer by increasing the adsorption of organic substrates using the long alkanes of CTAB.Concurrently,elemental sulfur was used to replace organosulfur to achieve a highly efficient and atom-economical multicomponent C-S coupling reaction.

Influence of initial check, information exchange, final accuracy check, reaction information nursing on the psychology of elderly with lung cancer

BACKGROUND As one of the fatal diseases with high incidence,lung cancer has seriously endangered public health and safety.Elderly patients usually have poor self-care and are more likely to show a series of psychological problems.AIM To investigate the effectiveness of the initial check,information exchange,final accuracy check,reaction(IIFAR)information care model on the mental health status of elderly patients with lung cancer.METHODS This study is a single-centre study.We randomly recruited 60 elderly patients with lung cancer who attended our hospital from January 2021 to January 2022.These elderly patients with lung cancer were randomly divided into two groups,with the control group taking the conventional propaganda and education and the observation group taking the IIFAR information care model based on the conventional care protocol.The differences in psychological distress,anxiety and depression,life quality,fatigue,and the locus of control in psychology were compared between these two groups,and the causes of psychological distress were analyzed.RESULTS After the intervention,Distress Thermometer,Hospital Anxiety and Depression Scale(HADS)for anxiety and the HADS for depression,Revised Piper’s Fatigue Scale,and Chance Health Locus of Control scores were lower in the observation group compared to the pre-intervention period in the same group and were significantly lower in the observation group compared to those of the control group(P<0.05).After the intervention,Quality of Life Questionnaire Core 30(QLQ-C30),Internal Health Locus of Control,and Powerful Others Health Locus of Control scores were significantly higher in the observation and the control groups compared to the pre-intervention period in their same group,and QLQ-C30 scores were significantly higher in the observation group compared to those of the control group(P<0.05).CONCLUSION The IIFAR information care model can help elderly patients with lung cancer by reducing their anxiety and depression,psychological distress,and fatigue,improving their tendencies on the locus of control in psychology,and enhancing their life qualities.